1. Field of the Invention
The present invention relates to a soil sampling probe for removing core samples from a desired depth below the surface of the earth.
2. Description of the Prior Art
It is common practice to obtain subterranean soil samples, also known as core samples, for a variety of purposes such as determining soil conditions prior to the construction of structures, determining the drainage characteristics of the soil, location of underground mineral deposits, studies of chemical dissipation and residue, determination of concentration of environmental contaminants, and investigation of hazardous waste sites. To be useful, the soil sample must be undisturbed and also the sampling device must sample soil only at the depth desired by the operator of the device.
Many soil sampling devices have been proposed in the prior art.
U.S. Pat. No. 3,042,124, issued to Andersson, shows a soil sampling probe having a conical piston within a sampling spoon. When the piston is in the lower most position, the sampling spoon abuts a flange on the piston rod to keep the spoon assembly from sliding up the piston rod during insertion into the ground. When the probe is at the desired depth the piston is drawn up while frictional forces between the spoon assembly and the earth keep the spoon assembly in place. With the piston in the upper most position within the spoon, the piston rod is rotated to bring lugs on the piston rod into locking engagement with recesses in the upper part of the spoon assembly. Further insertion of the probe then fills the spoon with soil.
U.S. Pat. No. 3,817,338, issued to Guest, shows a split barrel soil sampling spoon. Guest does not disclose how soil is prevented from entering the spoon before it reaches the desired depth.
U.S. Pat. No. 4,729,437, issued to Zapico, shows a soil sampling probe designed to be inserted into a preexisting well. The probe comprises a sampling spoon with a plug attached at the cutting end. When the probe reaches the bottom of the well, the plug is removed by pulling on a chord and the spoon is pushed into the soil to take a sample.
U.S. Pat. No. 4,848,484, issued to Clements, shows a soil sampling container with a hinged side cover. Clements does not disclose a closure for the cutting end of the sampling container.
U.S. Pat. No. 4,953,637, issued to Starr et al., shows a soil sampling probe wherein a series of tubular sleeves connected end to end are pushed into the ground. A conical piston acts to close the cutting end and is kept in place, during insertion into the ground, by a series of extension rods running along the entire length of the assembly of sleeves.
U.S. Pat. No. 5,186,263, issued to Kejr et al., shows a soil sampling probe where a conical piston is kept at the opening to the sampling spoon by a threaded plug at the top end of the spoon. When the desired depth is reached, the plug is removed and the piston is thus allowed to slide up within the spoon as the spoon is further inserted to take the core sample.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.